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antibiotics_staph

antibiotics for Rx of Staph. aureus

non-MRSA organisms

beta lactamase resistant penicillins

  • dicloxacillin
  • methicillin
  • penicillins combined with beta lactamase inhibitors such as clavulanic acid, sulbactam, tazobactam
    • eg. amoxycillin with clavulanic acid (Augmentin Duo Forte)

cephalosporins

other antibiotics

  • erythromycin
  • quinolones such as ciprofloxacin

MRSA organisms

  • MRSA contains a gene, mecA, which stops β-lactam antibiotics from inactivating the enzymes (transpeptidases) that are critical to cell wall synthesis
  • use of fluoroquinolones is associated with significantly increased risk of colonisation with MRSA
  • community acquired MRSA is a hybrid of hospital MRSA and community Staph and tends to be more virulent, although easier to treat than hospital MRSA
    • CA-MRSA may respond to co-trimoxazole, tetracyclines or clindamycin but is usually treated with vancomycin
  • teicoplanin
    • a structural congener of vancomycin that has a similar activity spectrum but a longer half-life

vancomycin intermediate-resistant Staphylococcus aureus (VISA)

  • linezolid
  • quinupristin/dalfopristin(synercid)
    • This antibiotic is not effective for left-sided endocarditis, or for pneumonia because it binds to surfactant and is inactivated.
    • The efficacy of daptomycin in patients with prosthetic heart valves has not been demonstrated.
  • tigecycline
antibiotics_staph.txt · Last modified: 2012/01/09 13:59 (external edit)